Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only indicate readOnlyHint=false, so the description carries the burden of behavioral detail. It transparently discloses that the tool creates a follow-up fact with follow_up_at and an optional note, connects it to the target object, and warns about the interim lack of a dated query tool. This is honest and useful, though it does not describe the exact return value or error behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded: first sentence states purpose with an example, second defines the data created, third gives an important limitation. Every sentence contributes necessary information, with no filler or repetition of the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple three-parameter mutation tool with no output schema, the description is largely complete: it covers what is created, how the object is linked, and how to retrieve follow-ups under the current limitation. The main omission is the response format, but that is minor for a create-style tool and does not block correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3 even with minimal description-level parameter detail. The description adds some meaning by naming the stored field follow_up_at and noting the optional note and object connection, but it largely restates what the schema already provides for the three parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action and resource: 'Set a dated follow-up about an object in the user's graph' and gives a concrete example. It clearly indicates this creates a follow-up fact rather than a calendar event or generic graph object, though it does not explicitly name sibling tools for differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description makes the tool's usage context clear: use it to attach a dated follow-up to a graph object. It also provides practical guidance for reading follow-ups back by listing fact objects and filtering on json_data.follow_up_at, effectively telling the agent what to do when a query tool is missing. It does not mention alternatives or exclusions explicitly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.